Yarn feeders commonly are vendor supplied parts or accessories for textile machines and particularly in loop-forming textile machines are often found in great numbers thereon. The yarn feeders each feed one yarn to a yarn-using station, such as a knitting station. The quality of the knitted goods produced depends decisively on the precision and reliability of the yarn feeders. On the one hand, this demands precision-manufactured yet on the other hand, the yarn feeders should be as simply embodied, economical, and simple to make and maintain as possible. Furthermore, they must perform reliably even if operated for relatively long periods without special maintenance and in particular without cleaning. Deposits of dust or fluff must not impair operation.
The goal also is to design a yarn feeder such that it can be adapted in a simple way to different kinds of use.
In the industry, yarn feeders are known that have a metal housing, which on one end has a clamping device for fastening to a yarn-using machine, such as a knitting machine. The housing forms a retainer for two ball bearings, which are disposed on the side of the housing remote from the fastening device. The ball bearings rotatably support a vertically disposed shaft, which on its lower end has a yarn guide drum and on its upper end has one or more toothed-belt pulleys. The toothed-belt pulleys can be coupled to the shaft via a displaceable coupling disk.
A yarn brake and a plurality of yarn guide elements are disposed upstream of the yarn guide drum. Further yarn guide elements are disposed downstream of the yarn guide drum. In addition, a shutoff lever and a yarn feeler lever are pivotably supported on the housing and actuate switches disposed in the interior of the housing in order to indicate a yarn break and to shut off the textile machine if necessary. For contacting a suitable electric line, connection means are provided on the fastening device, from which means electric lines lead to the appropriate switches in the interior of the housing. A signal light also is disposed on the yarn feeder and signals an error state accordingly.
Such yarn feeders have proven themselves in practice. However, they can be expensive to manufacture.